As an individual ages, the eye is less able to accommodate, or bend the natural lens, to focus on objects that are relatively near to the observer. This condition is known as presbyopia. Similarly, for persons who have had their natural lens removed and an intraocular lens inserted as a replacement, the ability to accommodate is absent.
Any number of lens designs have been used in attempt to correct for the wearer's presbyopia. Among the known designs are bifocal and progressive spectacle lenses. Additionally, multifocal contact and intraocular lenses and mono-vision contact lenses are known.
Monovision contact lenses provide one lens that corrects the wearer's distance vision acuity and that is worn on the dominant eye or eye that predominates for the individuals' distance vision. Additionally, a second lens that corrects the wearer's near vision acuity and is worn on the non-dominant eye is provided. These lenses are disadvantageous because they only correct for low order optical aberrations, such as defocus and astigmatism, leaving the lens wearer's higher order aberrations uncorrected.